Plum Island Surficial Geologic Map Sheet 2

Page 1

Massachusetts Geological Survey, Geologic Map, GM 13-01 Onshore-Offshore Surficial Geologic Map of the Newburyport East and Northern Half of the Ipswich Quadrangles, Massachusetts, Sheet 2 of 3 2013

Qgsc

-30

-30 v

Qgsc

-60

-15

Qss

Qsrt

-45

Seismic-Reflection Profile l114f1_2

Seismic-Reflection Profile l114f1_1

-45

Qdl

bedrock

Qdl

Qgsc

-60

Qmsc

-75

-75 bedrock

Qgsc

bedrock

-90

-1 m

laminated and bedded bedded; fine to coarse sand layers; some heavies and occasional shell hash rich layers

-2 m

-3 m

-90

bedrock

-105

MSL

occasional bedding and thin heavy mineral layers

-4 m

-105

V.E.: 20x

-2 m

9

largely homogenous, mica-rich medium to medium-fine sand; thinly laminated in some sections

-7 m

Sea floor

Lowstand delta (Qdl) foreset beds

-40 -50 -60 -70 -80 -90 Seafloor multiples

-100 1000 m

-110

-9 m

-10 m

-11 m

-12 m

-14 m

erosional contacts common very immature clay with dropstones

-15 m

immature fine silty sand

-13 m

Shore-Parallel Cross Section: B-B’ Projected Location: GPR Profile A

Elevation Relative to MSL (m)

Qb

0

g

g

g

Qd

Qs

-15

Qb

a

Merrimack River Qfc

d

Qb

g

a Qs

Qd

Qe

-30

Bend in PIG11 PID02 Section v g v g Qm v g d gd g d d d g gv d v g v

g d

Qe

Qe

Qtc Qm

Qgsc

Qgsc

V.E.: 20x 0

3

2

1

Qfc

Qb

d

8 Distance (km)

7

d/g

d

v

d d

Qd

d Qm Qgsc

Qe

Subaerial drumlin (Qtd) Qs d

Qgsc

9

10

Qb

d

0

Qe -15 -30

Qtd 12

11

14

13

PIG11 (sample core log)

PIG01

PIV03 PIG10

PIG12

PIV04

PID03

-12 m

-14 m

clay with minor silt

fine sand with rip-up clasts

weathered clay -18 m

-20 m unweathered clay

-22 m

-24 m

-26 m

silty, sandy clay

-28 m

-30 m dropstone

-32 m

massive clay

clay silt / very fine sand

-34 m

fine sand medium sand coarse sand / fine granules

15

coarse granules / pebbles

-36 m

silty, sandy clay 8 4 0 2 Mean Grain Size (phi)

Sample sediment core profiles. Modified from Hein et al. (2012). MSL: mean sea level. Note different vertical scales. Insets are pictures from cores showing key contacts: gravel lag of lowstand Parker River overlying glaciomarine clay in PIG11 (direct-push core); weathered to unweathered glaciomarine clay in PID02 (auger drill core). Color notations associated with pictures are from Munsell (2000).

Ground-Penetrating Radar Profile A PID01

-10 m

PID05

PID06

PID02 (sample core log)

PIV05

PIV06 PIG02

PIV07

1

0

0

25

75

-2

100

-3

125

-4

150

-5

175 200

-6 100 m

-7

Elevation Relative to MSL (m)

1

Qm

Qm

Qb

-1

250

50

Qb

75

Qb

-2

225 0 25

Qm

Qm

0

100 Qtc

-3 -4 -5

125 Qtc

Inlet Channel Complex I

Inletassociated bar

150 Qe

Inlet Channel Complex II

Qe

-6

GPR Profile B (below); continues to -15 m MSL

-7

175

Bar Qfc

200

Migrating esturaine tidal channels

Qe

Qe

TWTT (nanoseconds)

50

-1

Qe

TWTT (nanoseconds)

Elevation Relative to MSL (m)

PIG08 PIV01

PIV02 PID04

organics

Core Log Explanation

Cross section of line B-B’ (shown on map). Cross section is based on > 20 km of ground-penetrating radar (GPR) profiles (see sample lines below), ground-truthed with a series of sediment cores. Cores are labeled by type (v: vibracore; d: drill core; a: auger core; g: ‘Geoprobe’ direct-push core) and are color-coded by source: purple - McIntire and Morgan (1964); blue - McCormick (1969); orange - Rhodes (1973); brown - Costas and FitzGerald (2011); and red - Hein et al. (2012; this study). Cores PIG11 and PID02 (Hein et al., 2012) are shown in detail to right. Note bend in section. Location of GPR Line A shown on the cross section is a projected position: GPR Profile A is offset and subparallel to the cross section because GPR surveys were conducted entirely along roadways and, where possible, in Freshwater Marsh (Qm) deposits, to enhance penetration and resolution. Unit descriptions on sheet 1. Dashed lines denote inferred contacts. MSL: mean sea level; V.E.: vertical exaggeration.

PIG04

2 0 8 4 Mean Grain Size (phi)

B’ 15

Qm Qgsc

6

5

4

-16 m

Elevation Relative to MSL (m)

B

15

Cross Profile A-A’

bedded coarse sand to granule with occasional clay lenses

massive with occasional heavy mineral layers; gradational contacts; mica-rich

-16 m

unweathered silt and clay (Qgsc) Gley 1 5/5G

Seismic-reflection profiles (CONN05005 profiles l114f1, l114f1_1 and l114f1_2) collected using an EdgeTech Geo-Star FSSB system and a SB-0512i towfish at a 0.25 second shot rate, a 9-ms pulse length and a 0.5-6.0 kHz frequency sweep. Trace lengths were adjusted between 100–200 ms to account for changes in water depth. The SB-0512i was towed approximately 10 m astern and 3 m below the sea surface. Navigation was obtained from the GPS receiver mounted above the interferometric sonar head. On the basis of horizontal offsets between the towfish and GPS receiver, the positional accuracy was estimated to be ± 20 m (Barnhardt et al., 2009). Seismic-reflection profiles were post-processed using SIOSEIS and Seismic Unix software packages (see Barnhardt et al., 2009 for detail). Locations of seismic-reflection profiles are shown in Shore-Normal Profile (A-A’, above). A constant seismic velocity of 1500 m/s through both water and sediment was used to convert travel time to depth. TWTT: two-way travel time. Note that profile scale is same as that of Shore-Normal Cross Section (A-A’).

-30

erosional contact

Elevation Relative to MSL (m)

-20

-8 m

0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.10 0.11 0.12 0.13 0.14 0.15

Unit Qfc

Seismic-Reflection Profile l114f1_2

TWTT (seconds)

Seismic-Reflection Profile l114f1_1

Seismic-Reflection Profile l114f1

gradational contact

-6 m

coarse lag (Qfc) Gley 1 4/10Y

10 12 11 15 14 16 18 13 17 Distance (km) Cross section of line A-A’ (shown on map). Eastern section of cross section is based on high-resolution Chirp seismic-reflection data (Barnhardt et al., 2009; see sample seismic-reflection profile below), groundtruthed with surficial sediment samples (not shown) and one offshore vibracore. Western section is ground-truthed with a series of vibracores and generalized stratigraphy from several drill auger cores located along Plum Island (closest is located 1 km south of line; see “Shore-Parallel Cross Section: B-B’” below). All vibracore locations (“v”) are color-coded by source: purple - McIntire and Morgan (1964); blue - McCormick (1969); green - Edwards (1988) / Oldale and Edwards (1990). Auger drill core (“d”) is from this study; core location is projected onto cross-section line. Note bend in section. Unit descriptions on sheet 1. Dashed lines denote inferred contacts. MSL: mean sea level; V.E.: vertical exaggeration.

coarse laminations to thin beds

-8 m

glaciomarine clay (Qgsc) Gley 1 5/10GY

8

7

massive sand

-6 m

glaciomarine silt (Qgsc) 2.5Y 7/3

6

5

4

10 cm

3

2

1

coarse laminations to thin beds

-4 m

Unit Qgsc

0

Unit Qm

MSL

-5 m

Detail

modern organics

Unit Qgsc

Seismic-Reflection Profile l114f1

1m

0

5 cm

Elevation Relative to MSL (m)

Qss

Qe

Qgsc

-15

modern mean sea level

weathered silt and clay (Qgsc) 5Y 4/2

0

modern organics

fine sand Gley 1 7/N

v v vv v v v v

Lithology

Detail

fine lag (Qfc) Gley 1 5/N

Qft

Qrs

15

PID02

Unit Qm

Qtt

Lithology

A’

Unit Qb

15

Qgsc Qtt

PIG11

Elevation Relative to MSL (m)

A

Cross Profile B-B’ Qd Qb Qs d Bend in vv v v vv v v v v v Section

Sample Core Logs

Unit Qtc

Shore-Normal Cross Section: A-A’

Unit Qb

Address: 269 Morrill Science Center, 611 North Pleasant Street, Amherst, MA 01003 Phone: 413-545-4814 E-mail: sbmabee@geo.umass.edu WWW: http://www.geo.umass.edu/stategeologist

Unit Qe

Massachusetts Geological Survey University of Massachusetts, Amherst

225 250

Ground-Penetrating Radar (GPR) Profile A: Processed (upper) and interpreted (lower) radargram collected across central Plum Island (see location on Cross Section B-B’) using a GSSI SIR 2000 GPR with a 200 MHz antenna. Data were post-processed using a combination of Radan (GSSI) and RadExplorer (DECO-Geophysical Co. Ltd.) software packages.. TWTT: two-way travel time; MSL: mean sea level. Dashed lines in upper image indicate locations of cores. Unit descriptions are on sheet 1. Regions of signal loss in radargram are due to shallow muddy units. Graphic core logs employ same color scheme as given for Sample Core Logs (top right). Black box with arrows indicates location of GPR Profile B.

Ground-Penetrating Radar Profile B PIG01

Map Data Sources PID01

PIG11 (sample core log)

100 -4

150

-6

200

-8

250

-10

300

-12

350

TWTT (nanoseconds)

Elevation Relative to MSL (m)

Map of data sources used in creation of 5-m resolution joined digital elevation model (DEM). DEM is based on bathymetric data collected in offshore region using a RESON 8101 multibeam echosounder operating at a frequency of 240 kHz and a SEA SwathPlus 234 kHz interferometric bathymetric system (Barnhardt et al., 2009). Onshore topography derived from coastal Light Detection and Ranging (LiDAR) data from the Plum Island Ecosystems Long Term Ecological Research Station (Valentine and Hopkinson, 2005) and the U.S. Army Corps of Engineers (2009). Additional bathymetric data derived from Massachusetts digital terrain models (DTM); see respective publications listed below for details. Dashed black line indicates the location of the modern mean low-water shoreline, mapped by Applied Coastal Research and Engineering in 2009 using 2005 LiDAR data.

50

-2

Elevation Relative to MSL (m)

Valentine and Hopkinson, 2005 (LiDAR)

high backscatter

Mass GIS Digital Terrain Models

Qm Qb

Qtc

Inlet Channel Complex I

100 150

Qfc Qe

-8 -10

200 Transgressive Channel Fill Deposits

Qfc

Sub-Bottom Geophysical Data

50

Qb

Qtc

Qe

250

Lowstand Channel Fill Deposits

300 350

Qgsc

low backscatter

450 0

TWTT (nanoseconds)

Qm

-6

-14

Explanation

Water surface

-2

-12

Barnhardt et al., 2009 (bathymetry)

U.S. Army Corps of Engineers, 2009 (LiDAR)

25 m

0

-4

Acoustic-backscatter intensity data overlain on hillshaded digital elevation model. Data were collected with a RESON multibeam echosounder operating at a frequency of 240 kHz in the offshore region and a Klein 3000 dual-frequency sidescan sonar (132/445 kHz) in the nearshore (Barnhardt et al., 2009). Backscatter intensity is an acoustic measure of the hardness and roughness of the sea floor. In general, higher values (light tones) represent rock, boulders, cobbles, gravel and coarse sand. Lower values (dark tones) generally represent fine sand and muddy sediment. Dashed red line: modern mean low-water shoreline.

Explanation

400 -14

Acoustic Backscatter Data

Topography

No Data

0

0

Qgsc Erosional Contact

400 450

Ground-Penetrating Radar (GPR) Profile B: Processed (upper) and interpreted (lower) radargram collected across the northern inlet sequence (Inlet Channel Complex I) and lowstand Parker River fluvial channel in central Plum Island. Data collected using a Mala ProEx GPR with a 100 MHz antenna. Data were post-processed using a combination of Radan (GSSI) and RadExplorer (DECO-Geophysical Co. Ltd.) software packages. TWTT: two-way travel time; MSL: mean sea level. Dashed lines in upper image indicate locations of cores. Unit descriptions are on sheet 1. Graphic core logs employ same color scheme as given for Sample Core Logs (top right).

Tracklines of geophysical sub-bottom data overlain on hillshaded digital elevation model. Offshore seismic-reflection profiles were collected as part of this study with an Applied Acoustic Engineering surface-towed boomer system (CAT200). Shallow (~8 m) ground-penetrating radar (GPR) profiles were collected using a GSSI SIR-2000 with a 200 MHz antenna. Deep GPR profiles (~16 m) were collected using a Mala Geosciences ProEx with a 100 MHz antenna. Other geophysical data collected as described in respective publications. Dashed red line: modern mean low-water shoreline. Explanation Barnhardt et al., 2009 (seismic) Costas and FitzGerald, 2011 (GPR) Oldale et al., 1983 (seismic) This study (seismic) This study (GPR)

Sediment Cores / Surficial Sediment Samples

Mapping Responsibilities

Locations of sediment cores and offshore surficial sediment samples. ss: grab sample; c: sediment core. Sediment cores include vibracores, auger cores, drill cores, wash bores, and direct-push cores, as described in respective publications. Dashed red line: modern mean low-water shoreline.

Responsibilities for data collection in map area, overlain on simplified geologic map. Most offshore data sources (backscatter, bathymetric data, shallow seismic, and majority of bottom grab samples) and preliminary mapping provided by Barnhardt et al. (2009). Onshore mapping derived from surficial geologic maps of Stone et al. (2006). Dashed red line: modern mean low-water shoreline.

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Barnhardt et al., 2009 (ss) Costas and FitzGerald, 2011 (c) Edwards, 1988 / Oldale and Edwards, 1990 (c) Hartwell, 1970 (c) Massachusetts State Boring (c) McCormick, 1969 (c) McIntire and Morgan, 1964 (c) Rhodes, 1973 (c) Ward, L., unpublished (ss) Hein et al., 2012 / this study (drill core) Hein et al., 2012 / this study (vibracore) Hein et al., 2012 / this study (’Geoprobe’ core) This study (ss)

Barnhardt et al., 2009 Stone et al., 2006 This study

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ONSHORE-OFFSHORE SURFICIAL GEOLOGIC MAP OF THE NEWBURYPORT EAST AND NORTHERN HALF OF THE IPSWICH QUADRANGLES, MASSACHUSETTS

The views and conclusions contained in this document are those of the authors and should not be interpreted as necessarily representing the official policies, either expressed or implied, of the U.S. Government, the Commonwealth of Massachusetts, the Commonwealth of Virginia, the Massachusetts Geological Survey, Boston University, the Virginia Institute of Marine Science, or the University of Massachusetts.

SHEET 2: Representative Map Cross Sections, Sample Core Logs and Data Sources By Christopher J. Hein, Duncan M. FitzGerald, Walter A. Barnhardt and Byron D. Stone 2013

Explanation

Completion of this map was supported by the U.S. Geological Survey, National Cooperative Geologic Mapping Program, under assistance Award Nos. G09AC00216 and G10AC00179. The crew of the F/V Venture (Gloucester, MA), Dann Blackwood, Emily Carruthers, Gene Cobbs Jr., Nicholas Cohn, Mary Ellison and Allen Gontz are acknowledged for their contributions in the field and lab. Finally, Wayne Newell, Joe Kelley, Ralph Lewis and Janet Stone are acknowledged for their careful reviews that have greatly enhanced the quality of this map.

Citation: Hein, Christopher J., FitzGerald, Duncan M., Barnhardt, Walter A., and Stone, Byron D. 2013. Onshore-offshore surficial geologic map of the Newburyport East and northern half of the Ipswich Quadrangles, Massachusetts. Massachusetts Geological Survey, Geologic Map GM 13-01. Scale 1:24,000. 3 sheets and digital product: Adobe PDF and ESRI ArcGIS database. This map was produced on request directly from digital files (PDF format) on an electronic plotter. This product supercedes Massachusetts Geological Survey OFR 10-01 and OFR 11-01. A digital copy of this map (PDF format), including GIS datalayers, is available at www.geo.umass.edu/stategeologist


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